Create your own invisible defense shield!

Every living human body is surrounded by an electric field, which may potentially be detected at a few meters’ distance. Even if this can only be detected at a distance of a few centimeters (as opposed to millimeters), the applications are legion.

Consider now that the phenomenon of capacitance is entirely dependent on the existence of electric fields. If, therefore, a human body should approach the positive plate of a capacitor, the body’s electric field will cause the value of the capacitor to rise.

In the Body Detector circuit described here, this is detected by means of an RC (resistance-capacitance) oscillator. As the value of C rises, so the frequency of the oscillator drops. All that remains is to detect this drop in frequency to obtain some very interesting results.